Some people are such impressive altruists that they seem to us to already be doing more than enough. And yet they see themselves as compelled to do even more. Can our view be reconciled with theirs? Can a moderate view of beneficence's demands be made consistent with a requirement to be ambitiously altruistic? I argue that a reconciliation is possible if we adopt a dynamic view of beneficence, which addresses the pattern that our altruism is required to take over time. (...) This frees up theoretical space for understanding how a moral duty of self-development can intersect with the requirements of beneficence, so that the amount that we are required to sacrifice increases without our beneficence becoming immoderate. (shrink)